Project Summary/Abstract. This R21 application in response to PA-08-168 (Secondary Analysis of Existing Alcohol Epidemiological Data) proposes a mixed methods investigation of mediators of substance use/abuse among sexual minorities with additional emphasis on women. Despite growing evidence of disparities in risks for hazardous and other drug use among sexual minorities, there is a death of research that explicitly examines factors that may mediate such problems in these population subgroups. The sample will be divided into subgroups based on sexual/identity and behavior questions (lesbian/gay identified, bisexual identified, and heterosexual identified with same sex partners and, finally, exclusively heterosexual men and women). The first specific aim is primarily quantitative, analyzing secondary combined data from the National Alcohol Surveys collected in 2000-2001 (NAS10), 2005-2006 (NAS11) and data currently being collected 2009-2010 (NAS12). The second aim is to conduct qualitative interviews with a subgroup of 48 (12 in each group) women drawn from the NAS12 respondents to do depth exploration of the quantitatively measured mediators and seek to understand other, unmeasured pathways, that may contribute to heavier drinking and alcohol related problems. The NAS is a unique data source ideally suited to the first aim of this study since it includes numerous theoretical mediators of substance use as well as basic alcohol epidemiology variables. Mediators include both individual and contextual markers suggested by the literature including stress, social support, sense of coherence, impulsivity and sensation seeking, past experiences of trauma, and frequenting bars and other drinking contexts. Analysis of the NAS10 data by the two proposed PIs revealed significant differences among these subgroups on substance use measures, particularly among women. Additionally, initial investigation of some mediators found substance use predictors varied as a function of gender and sexual minority subgroup. The qualitative interviews will also explore novel topics and emerging theories for which no quantitative data is available. PUBLIC HEALTH RELEVANCE: This project furthers our understanding of the increased risk for hazardous alcohol use, alcohol-related problems, and drug use among sexual minorities, which is especially pronounced among women. Such knowledge about the dynamics of specific disparities in health risks was identified by the Institute of Medicine (IOM) report on lesbian health as fundamental to development of both clinical and public health interventions. Understanding specific factors that may increase or buffer risk for hazardous drinking among sexual minorities (and non-minorities) provides a foundation for the development of culturally and gender appropriate prevention and intervention strategies.